From: m-karicheri2@ti•com (Murali Karicheri)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: keystone: add a work around to handle asynchronous external abort
Date: Fri, 14 Aug 2015 17:55:09 -0400 [thread overview]
Message-ID: <55CE63BD.2060107@ti.com> (raw)
In-Reply-To: <1439562059.13210.61.camel@pengutronix.de>
On 08/14/2015 10:20 AM, Lucas Stach wrote:
> Hi Russell,
>
> Am Freitag, den 14.08.2015, 15:09 +0100 schrieb Russell King - ARM
> Linux:
>
> [...]
>
>>
>> What causes the abort? We shouldn't be adding hacks like this to the
>> kernel without having the full picture...
>>
>
> some of the issues with tracking down such imprecise external aborts are
> due to the fact that we only enable the signaling of those aborts on
> entering the user-space. So the first schedule() crashes on the previous
> dangling abort.
>
> I'm carrying this patch locally to enable imprecise aborts much earlier
> in the boot process. I think it has already been on the list some times,
> but apparently it has fallen through the cracks. If you agree that this
> is the right thing to do I can do a proper repost.
Lucas,
Would you mind sharing the code? Does that help in root causing where it
actually happens? I have spend considerable time debugging this, but so
far not successful.
Murali
>
> Regards,
> Lucas
>
> ---------------------->8---------------------------------------------
>>From bb9117d94cc2f1061dc364f42c446ccd9191e869 Mon Sep 17 00:00:00 2001
> From: Lucas Stach <l.stach@pengutronix•de>
> Date: Thu, 19 Feb 2015 18:12:50 +0100
> Subject: [PATCH] ARM: Add imprecise abort enable/disable macro
>
> This patch adds imprecise abort enable/disable macros.
> It also enables imprecise aborts when starting kernel.
>
> Changes in v2:
> Only ARMv6 and later have CPSR.A bit. On earlier CPUs,
> and ARMv7M this should be a no-op.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st•com>
> Signed-off-by: Lucas Stach <l.stach@pengutronix•de>
> ---
> lst: rebased on v3.19
> ---
> arch/arm/include/asm/irqflags.h | 10 ++++++++++
> arch/arm/kernel/smp.c | 1 +
> arch/arm/kernel/traps.c | 4 ++++
> 3 files changed, 15 insertions(+)
>
> diff --git a/arch/arm/include/asm/irqflags.h
> b/arch/arm/include/asm/irqflags.h
> index 3b763d6652a0..8301f875564e 100644
> --- a/arch/arm/include/asm/irqflags.h
> +++ b/arch/arm/include/asm/irqflags.h
> @@ -51,6 +51,14 @@ static inline void arch_local_irq_disable(void)
>
> #define local_fiq_enable() __asm__("cpsie f @ __stf" : : : "memory",
> "cc")
> #define local_fiq_disable() __asm__("cpsid f @ __clf" : : : "memory",
> "cc")
> +
> +#ifndef CONFIG_CPU_V7M
> +#define local_abt_enable() __asm__("cpsie a @ __sta" : : : "memory",
> "cc")
> +#define local_abt_disable() __asm__("cpsid a @ __cla" : : : "memory",
> "cc")
> +#else
> +#define local_abt_enable() do { } while (0)
> +#define local_abt_disable() do { } while (0)
> +#endif
> #else
>
> /*
> @@ -130,6 +138,8 @@ static inline void arch_local_irq_disable(void)
> : "memory", "cc"); \
> })
>
> +#define local_abt_enable() do { } while (0)
> +#define local_abt_disable() do { } while (0)
> #endif
>
> /*
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index 86ef244c5a24..7b6b93cabef4 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -378,6 +378,7 @@ asmlinkage void secondary_start_kernel(void)
>
> local_irq_enable();
> local_fiq_enable();
> + local_abt_enable();
>
> /*
> * OK, it's off to the idle thread for us
> diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
> index 788e23fe64d8..466726ba9bdb 100644
> --- a/arch/arm/kernel/traps.c
> +++ b/arch/arm/kernel/traps.c
> @@ -881,6 +881,10 @@ void __init early_trap_init(void *vectors_base)
>
> flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
> modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
> +
> + /* Enable imprecise aborts */
> + local_abt_enable();
> +
> #else /* ifndef CONFIG_CPU_V7M */
> /*
> * on V7-M there is no need to copy the vector table to a
> dedicated
>
--
Murali Karicheri
Linux Kernel, Keystone
next prev parent reply other threads:[~2015-08-14 21:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-11 19:13 [PATCH] ARM: keystone: add a work around to handle asynchronous external abort Murali Karicheri
2015-08-14 14:04 ` Murali Karicheri
2015-08-14 14:09 ` Russell King - ARM Linux
2015-08-14 14:20 ` Lucas Stach
2015-08-14 21:55 ` Murali Karicheri [this message]
2015-08-14 21:56 ` Russell King - ARM Linux
2015-08-17 14:09 ` Murali Karicheri
2015-08-14 15:14 ` santosh shilimkar
2015-08-14 21:53 ` Murali Karicheri
2015-08-14 21:56 ` Russell King - ARM Linux
2015-08-17 22:12 ` Murali Karicheri
2015-08-17 22:47 ` Russell King - ARM Linux
2015-08-18 3:09 ` santosh.shilimkar at oracle.com
2015-08-18 8:13 ` Russell King - ARM Linux
2015-08-18 8:28 ` Lucas Stach
2015-08-18 12:06 ` Afzal Mohammed
2015-08-18 8:28 ` Jisheng Zhang
2015-08-18 14:49 ` Murali Karicheri
2015-08-18 20:25 ` Murali Karicheri
2015-08-15 0:01 ` santosh.shilimkar at oracle.com
2015-08-14 14:11 ` Lucas Stach
2015-08-17 14:11 ` Murali Karicheri
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